This paper draws attention to salient demographic features of the youth development in South Africa. Relatively large cohorts of people were born in the period when total fertility rate was fairly high in South Africa. As these cohorts grow into each age group, the structure for the national population pyramid is significantly affected. The issue of interest here is the momentum for future increases in the overall size of the population that is built into the age structure of the total population by past demographic dynamics. This feature is described in elementary population textbooks but has not been seriously studied in its own right partly because of a research culture that was dominated by concerns about high levels of fertility and rapid population growth in Africa.